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    Re: Celestial Navigation Data from USNO--alternative
    From: Bill Ritchie
    Date: 2019 Nov 30, 15:23 -0800

    Frank, Thank you for all the helpful information re Delta T.

    You asked for the values of ΔT that, after rounding to 1 place of decimals, give USNO quoted values for the MOON on 2030 OCT 22 at 16:45:30 UT. DR. N41° 29.0' W071° 24.5'. I think the value used must lie between 79 seconds and 86 seconds.

    GHA: Quoted 127° 29.2’. ΔT 75” gives 127° 29.25’. ΔT 86” gives 127° 29.15’. So ΔT between 75” and 86”.

    Dec: Quoted N4° 48.3’. ΔT 79” gives N4° 48.35’.   ΔT 86” gives N4° 48.33’. So ΔT now between 79” and 86”.

    Hc: Quoted 28° 10.2’. ΔT 79” gives 28° 10.21’. ΔT 86” gives 28° 10.24’. ΔT confirmed between 79” and 86”.

    Zn: Quoted 249.7°. ΔT 79” gives 249.72°. ΔT 86” gives 249.72°. ΔT confirmed between 79” and 86”.

    Bill Ritchie 50N 003W

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